Internal-combustion engine



Sept. 2. 1924. 1,506,950

J. W. SMITH INTERNAL coususnou ENGINE Filed Nov. 12. 19.2 s sheets-sham 1 WITNESSES: INVENTOR:

By P Ff A TTORNEYS.

Sept. 2, 1924, 1,506,950

J. w. SMITH INTERNAL COMBUSTI ON ENGINE Filed Nov. 12. 1821 5 Sheets-Shoot 2 75 77 Hi2 I. 50 35 76 65 WITNESSFS: 1Z6 INVENTOR:

y -13E By W A TTORNEYS.

Sept. 2, 1924. 1,506,950

J. W. SMITH INTERNAL COMBUSTION ENGINE Filed Nov. 12, 192 5 Sheets-Shut W1 TNESSES: I N V EN TOR:

ATTORNEY Sept. 2

J. W. SMITH INTERNAL COMBUSTION ENGINE filled Nov. 12, 1921 5 Sheets-Shut" v n. i.

Wm w Mr N @NPK Se t, 2, 1924, 1,506,950 J. w. SMlTH I INTERNAL COMBUST ION ENGINE Filed NOV. 12, 1921 5 Sheets-Sheet 5 FIGhTZ- V/Hllllllll jiiiiifi f 16 1% 2;

J IGM- WITNESSES: I I N VE N TOR:

Patented Sept. 2, 1 924.

UNITED STATES 1,506,950 PATENT orrlca.

a JOHN W. SMITH, PHILADELPHIA, PENNSYLVANIIA.

INTERNALfCOMBUSTION ENGINE.

Application filed November 12, 1921. Serial no. 514,598.

To all whom it may comern: i

Be'it known. that I, JOHN W. S MI'rH, a citizen of the United States, reslding at Philadelphia, county of Philadelphia, and. .State of Pennsylvania, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to internal combustion engines or motors, and is specially concerned with the cooling of such engines to prevent overheating. The principal object of my invention is to accomplish this cooling by means of the'atmospheric air in a thoroughly effective and satisfactory manner. The invention is applicable with great advantage to engines for the'propulsion of automobiles and air-craft.

While many attempts have been made to construct satisfactory air-cooled internal combustion engines, such attempts have hitherto failed of real success, in that the results attained have always been far inferior to those with water-cooling. Through my present invention, I have succeeded in securing an effectiveness of air-cooling equal or even superior to that of water-'cooling,- and this in a thoroughly convenient and practicable manner, not involving complicated or unduly expenslve forms or 'features of construction. Without as yet attempting to formulate my invention, I may render the following description of thebest embodiment of it known to me more readily intelligible by a brief preliminary explanation of the main featuresof that embodiment.

One important feature of the construction. here illustrated and described is the provision for cooling the engine cylinders at their" zone or region of combustion or explosion,-where the highest temperatures are developed, by means of highly thermoconductive cooling structures or elements extended to aflord radiating surface that may exceed the area of heat-absorption manyfold. Another important feature is a somewhat similar provision for cooling the exhaust valves (which when open are completely surrounded'by the -heated products of combustion) by meansof a highly thermo-.conductive cooling element or structure affording ample area for absorption of heat from and adjacent the valve stem,- though otherwiseisolated as far as possible from the heating influence of the exhaust,-

and extended to afford radiating" surface.

that may greatly exceed the, area of absorpt1on. The cooling or heat-dissipating action of these elements is supplemented and made more effective by cooling means for dissipating the heat from other portions of the 'cylinder structure besides the combustion zones and the exhaust valves, and by provisions for assuring ample flow of cooling air over the various radiating surfaces.

Qther valuable features and advanta es Wlll become apparent as the description proceeds. In the drawings, Fig.1 is a side view of an air-cooled multi-cylinder automobile engine that represents the best embodiment of my invention 'at present known to me, certain parts being broken away or in section. Fig. II 1s a cross section of the cylinder structure generally on a larger scale than Fig. I, taken as indicated by the line IIII in Fig. I, except as regards the cylinder heads, where the section is somewhat staggered so as to include both theintake and exhaust valves 1 Fig. III is a the cylinder structure with the cover of one of the valve gear housings in hori zontal section. I

'Figs. IV and V' are respectively a lan view and an elevation of the cylinder b ock, two, of the cylinders being shown" in axial section in Fig. V.

Fig. VI is a plan'view of a portion of a cooling element for. the combustion zones plan view of a portion of 7 tratin-gfeatures of; the valve-operating mechanism, taken as indicated by the lines X-X in Fig. II. Fig. XI is a fragmentary sectional view illustrating details .of construction, taken as In the. engine here shown (see igs. I,

indicated by, the line XIXI in F i III. W

II, III, IV and V), the cylinders 1, 1 are haust passage.

ranged side by side in a row or series along the crank case 10, separated by interspaces 2', 2. vFrom opposite sides of the row of cylinders 1, 1 project integral longitudinal heatradiating fins 8, and on thefore and aft sides of each cylinder are similar but shorter fins 9. Besides the radiating means 8, 9, there are additional cooling elements 15 at the combustion zones or chambers 11 (which are here the clearances in the upper ends of the cylinders) where the greatest amounts of heat are developed-.1 These cooling elements 15 comprise annular heat-absorbing portions 17 see, also, Figs. VI and VII) surrounding the combustion chambers, and plate-like heat radiating means 20, 21, of ample. surface, connected to the portions 17, at isolated points, by "heat-conducting and radiating members or web's 22, 23, 24. As here shown, the annuli 17, 17 are interposed between the main, lower barrel or body portions of the cylinders 1, 1 and the cylinder heads 30, 30, and form the peripheral walls of the combustion zones or chambers 11, ingdirect contact with the hot gases therein.

In the cylinder heads 30 are the branching intake passages or inlets 35, supplied with the motive fluid by 'a manifold 45, and the exhaust passa es or outlets 36, through which spent pro ucts of combustion 'escape to the exhaust manifold branches 4:6.

The passages 35 and 36 terminate in conical seats 37 and 38 for admission and exhaust valves 39 and 40..

"from the heads to permit access and-pas? sage of cooling air between, and also to thermo-insulate or isolate them from the heatin influence of the exhaust passage. Each 0 these coolin elements 50 has an integral sleeve or hollow boss portion about the large exhaust valve stem 61 that afi'ords amply extended bearing for transmission or absorption of heat from said stem. The lower boss portion 60 extends down around the stem 61 into the exhaust passage. or conduit 36, with a gas-tight fit over a minimum zone-of contact in the upper'wall of the ex- This lower boss portion of the sleeve 60 not only affords bearing for the stem 61,- but also shields or protects it from the exhaust gases by itself absorbing their heat. As shown, the cooling elements 50 serve as housings for enclosing parts of the valve-actuating mechanisms or gear for the respective cylinders, and are made separate from one another, eachin upper and lower halves secured together by bolts 53. The cylinder heads 30 have heat'radi'ating fins 41, and the lower housing halves have radiating fins 88 and 89.

Recurring, now, to the cylinders 1, 1 it will be seen from Figs. IV and V that hey are interconnected by fore and aft webs 3 extending the greater part of their length,

as well as by base and top flanges 4, 5, 6

vidual cylinders themselves, and some from 4 the outer sides of the webs'3. The outer edges of theseuniformly spaced fins 8 being (for the mostpart) in one strai ht line, it will be seen that their several heig ts and surface areas vary in correspondence with the obliquity and extent of cylinder wall served by each. The like is true of the fins 9. In the midst of the top flange portions 5 interconnecting the cylinders are elongated transversely extending apertures 13 for downward passage of air to cool the adjacent finned fore and aft. sides of the cylinders 1, 1. The cylinders 1, 1 should are be of wear-resisting material (such as gray iron), preferably cast en bloc, as shown, and integral with their various fins, webs, and flanges.

Referring, now, to Figs. 1, II, VI, VII, and VIII, it will be seen that the cooling elements 15, .15 for the several cylinders are connected or united in one fore and aft structure or member. This structure comprises a narrow or shallow central or tion 16 made up of the narrow annuh 17 and their interconnecting webs 19, which mal conductivity, it is usually preferable that if the piston 12 is to overtravel the annulus 17, the latter be made so much larger internally than the cylinder body 1 as not to come in contact with the piston. (See Fig.

II.) At a substantial distance on either side, the central portion 16 is flanked by the radiating plate structures 20 and 21, of considerably greater vertical depth or width, extending alongside the row of annuli 17. The

isolated webs 23 by which the plate 21 is supported from the structure 16 are individually of the fin-like .stream-linc configuration indicated in Fig. VIII. At the left-hand side 22 are mer ed together or consolidated into much heavier webs 24, which are bored and bushed at 25 to take the spark-plugs 26 of the element 15, some of the thicker webs (Figs. II andVII). From about the same vertical depth or width as the annuli 17, the

webs 22, 23 and 24 are widened or flared, at

their outer ends (where they join the plates and 21), for the sake of greater rigidity and better distribution of heat to the upper and lower edges of the plates 20 and 21. From the outer sides of the plates 20 and 21 project transverse vertically. extending radiatin 'fins,'28, 28 (i. e., extending longitudina ly of the cylinder like the fins 8 and the webs 22) that serve to amplify the radiating-surface and facilitate the dissipation of heat from the annuli 17. In the aggregate, the webs 22, 23 and 24 are ofample metallic cross section to conduct the heat readil and quickly to theplates 20 and 21,

I and a so afford a certain amount of radiating surface of their own. The plates 20 and 21 extend outside of and overla the cylinder heads '30 and their radiating s 41, longitudinally of the cylinders, at a suitable distance, as well as the cylinder bodies 1, 1 and their fins 8; Thus access of air to both outer and inner facesv of the plates 20 and 21 is freely permitted, and also free passage of air along these inner and outer faces to the cylinder fins 8. The coolin elements 15, 15 with their various parts ust described are preferably made integral, as by casting them en bloc. They should generally .be of the most highly thermo-conductive material that it isfeasible to use, particularly aluminum or aluminum bronze. g

As here shown (see Figs. I, II, and III), all the cylinder heads 30 are united in one member, which has upstandin bosses or webs 33 pierced for the reception of bolts 34 corresponding with those in the webs 19 and in the lugs 5 and 6. The heads 30 are separated by apertures 42 corresponding with the apertures 18 and 13. It will be observed that the intake passages 35 of adjacent cylinders merge for connection .to the branches of the intake manifold while each of the exhaust passages 36 is connected to a separate exhaust manifold branch 46. Between the exhaust outlets 36, the vertical radiating fins 41' (Fig. II) project from the heads 30 transversely of the row of cylinders, for the purpose of cooling the heads.

These fins 41 are vertically aligned with the cylinder block fins 8. The heads 30 are preferably of gray iron cast en bloc. Q

The coolin elements 15 are clamped between the cyllnder heads 30 and the cylinder bodies 1 by means of bolts 34 (already men-v tioned) whose own heads engage/the cylinder head bosses 33, and whose threaded lower ends take into thethreaded cylinder lugs. 5 and 6. Tightness between the annuli17 and the heads 30 and bodies 1 is insured by interposed gaskets 31 and 32, which are preferably made of highly thermo-conductive soft sheet metal,such as sheet aluminum about .040" thick. By initially taking up fairly hard on the bolts 34, they may be put under such tension as to assure tightness and close contact at these joints 'under all working conditions and variations of temperature; for while the aluminum coolin element'15 and 32) and the cylinder heads 30 and bodies 1 enables the elements 15 to conduct heat away from the abutting surfaces of heads and bodies, so as to assist in keeping these parts cool as well as the combustion zones of the cylinder walls.

Still referring to Figs. I, II, and III, it will be seen that the vertical radiating fins 88 that roject transversely from the side of the coo ing elements nearest the valve .will expand and contract more t an the iron stems 61 are aligned with the cylinder head fins 41 and the cylinder fins 8, while the vertical fins 89 that project fore and aft from the corresponding sides of the elements 50 are aligned (or at least those in thegroup toward the right in Fig. III) with the cylinder fins 9 and the openings 42, 18, and 13 in the intervening parts.- In the present in stance, only the lower halves of the elements 50 carry the fins 88 and 89. Each cooling element or housing 50 is spaced from the cyla inder head 30 by a shoulder 55. on a hollow,v

the cylinder ead 30by standards or columns a 76 .whose reduced lower ends extend through holes -in'the housing bottom and are threaded into circular spacing-bosses 79 on the head. These columns 76 serve to support the valve-operating mechanism, as hereinafter described.

This mode of mounting the element 50 on the head 30 minimizes direct transmission of heat to the element 50 from'said head,

and especially from; the hot exhaust passage 36. The exhaust valve stem sleeve 61 does,

indeed, make contact withthe highly heated I exhaust conduit' 36 and form a-' direct thermo-conductive metallic connection therefrom to the element 50; but this contact and connection is of the minimum area consistent with gas-tightness, as already explained.

The cooling elements 5(lishould generally beof the most highly thermo-conductive metal,

such as aluminum or aluminum bronze.

The exhaust valve stem 61 should not only be of quite large diameter (as shown, more than one-third'th'at of the head 40), but

should preferably be bored out to asmall thickness clear down to the valve head 40 and internally threaded,- and should have a core 62 of highly thermo-conductive metal (aluminum or bronze) ,screwed in as tight as possible to insure good contact,to assist in conducting'the heat away from the head 40 to the sleeve 60. The stem 61 should have as close a working fit in the sleeve 60 as consists with the avoidance of undue friction, to facilitate the transmission of heat.

Referring, still, to'Figs. I, II and III, it will be seen that the engine is almost entirely enclosed in a. sheet metal casing 90 whose lower portion 91 surrounds the upper half of the crank case 10, and whose upper trunk-like portion 92 envelopes the cylinders 1, 1 and many of the associated parts. The end walls 93 of the trunk 92 extend upward to the plane of division of the cooling ele- Flow of air for cooling is produced by a turbine fan 105 mounted on the engine shaft 107 in a cowling 110 opening from the lefthand end of the casing 90. (Fig. I.) The in clin'ed moving blades 108 attached to the disk 106 on the shaft 107 cooperate with blades 109 fixed to the interior of the cowling 110, and act to pass the air down through the trunk 91 over the cylinder structures and their cooling means.

Referring, now, to the right-hand side of the engine in Fig. II, it w ll be seen from the arrows that the air is drawn in between the upper edge of the sheet 96 and the sides of the housings 50, down through the vertical channels formed by plate 96, housing 50,

and fins 88, and over and around the exhaust conduits 36; down behind .the plate 21 through the vertical channels formed by the. latter and'the cylinder walls in conjunction with the fins 41, webs 23 and the fins 8; on down over and amongst the fins 8, and into the casing 91. Air is also drawn in between the upper edge of the trunk side 94 and the plate 21, down along the outer face of this late through the vertical channels formed y the plate in conjunction with the trunk side 94 and the fins 28; this air finally issues from the lower ends of these channels and is deflected amongst the fins 8 by the trunk wall offset 95, so as to mingle with the air stream already described. At the left of the engine, the same double air flow.

occurs,except for the difference entailed by the absence of any'plate 96 or fins 88. Between the housings 50, air is drawn down through the vertical channels formed by them and their fins 89. At the left, this air is drawn over the intakeconduits 35 and behind the plates 21; and toward the right, it is drawn down through the vertical openings 42, 18, and 13 into the vertical channels formed in the interspaces 2, 2 by the adjacent cylinder sides and the fins 9,finally striking the bottom cylinder flanges 4 and being deflected to right and left out into the casing 91 below the lower ends of the fins 8 and 9 (which terminate about at the lowermost positions of the upper ends of the pistons 12). At either end of the set of cylinders, the air flows down between the trunk ends 93 and the adjacent surfaces of the various parts (50, 30, 15, 1) very much like that entering between the housings 50.

Thus the air is caused to flow over the radiating means and-surfaces of the various parts and cool them. effectively.

Most important to the success of air cooling is the heat-dissipating action of the metalliccooling elements 15 and 5O- for the combustion zone and the exhaust valve. By extending these to a suificient distance from their areas of heat absorption, it, is practicable to gain room for amplification of their extensive radiating surfaces to any degree really required; while by directing this expansion or extension of their radiating surfaces longitudinally of the cylinde"s, especially in the case of the element 15,- it is possible to keep the cylinder structures compact. It is also important, of course, that these metallic cooling elements be so arranged as to absorb heat adequately from the critical portions of the cylinder structures.

It remains to describe briefly the valve gears or actuating mechanisms, which are in part enclosed in the housings 50,-or one of these mechanisms. As shown in Figs. II and III, the intake and exhaust valves 39 and 40 are urged toward their seats 37 and 38 by concentric helical compression springs 80 and 81, 62 and 63, acting between the bottom of the housing v and disks 82 and 64 secured to the upper ends of the respective valve stems 83 and 61. The upper ends of the ,valve stems 83 and 61 are connected by ball and socket joints with the arms of actuating levers 85 and 66, respectively. These levers 85 and 66 have spherical-bottomed sockets for rocking on hemispherical parts which bear-and are free to slip as required by the rocking of the leverson the fiat ends of the respective adjusting screws 86 and 67, whose upper ends are threaded through an overhanging bracket plate 73 above the levers and have lock nuts '7 5. 4

The levers 85 and 66 are themselves opvalves. I 7

Having thus described my invention, I

ball and socket joints, and extending down into the crank casing 10 through a tubular casing 71 (of oblong cross-section) whose upper end is clamped to the bottom of the housing 50 by a plate 72 bolted thereto. The push-rod actuated ends of the levers 85 and 66 have flat-faced lugs 87 and 78 by which they are guided in vertical slots or slideways in a web 77 depending from the bracket plate 73. The rods may be actuated by any suitable mechanism," such as cams 115 on the usual cam-shaft 116 in the crank case 10. As shown, the lower ends of the rods 70 have ball and socket connection with plunger heads 120 sliding in ways 121 mounted in a housing 122 bolted at 123, 123

to the upper sideof the crank case 10, and these plunger heads 120 carry rollers 12& for engaging the cams .115. The lower end of the casing 71 has a close fit in the upper side of the housing 122. One end of the bracket plate 73 that carries the fulcra 86 and 67 is' screwed fast (and secured by a lock nut 125) on the upper end of a supporting column 74 that extends down through the casing 71 to the crank case 10', where it is anchored and supported The lower end of the column is screwed fast andsecured in the housing 122, between the rods 70..

The other end of the bracket late 73 is supported and secured (see Fig. per ends of the two short columns 76, which are anchored and supported on the cylinder head 30 as already described. Thus the,

bracket plate 73 has a three-point support; at one end, adjacent the push-rods 70, on the column 74 fastened to the crank case, and at the other end, adjacent the'valve stems 83 and 61, on the columns 7 6 fastened to the cylinder head. The column 74 being exposed to the same temperature conditions as the valve-operating rods 70, changes in length of the rods 7 0 are automatically compensated," and he ce do not afiect the adjustment of the valves as determined b the setting of the fulcra in the bracket 73. imilarly, the columns 76 are exposed to about the same temperature conditions as the valve stems 83 and 61, so' that changes in length of the latter are automatically compensated and do not afiect the adjustment of the claim:

tit)

\ 1. A metallic cooling member tor an internal combustion engine comprising a row of narrow annuli with interconnecting webs adapted to form the combustion zone walls of the engine cylinders; and wide radiating structures extending along said row of an: nuli at either side, separated from the annuli to permit access of air between, but connected to said annuii and their interconnectr I) on the up-- ing webs, at isolated points, by heat conducting and radiating members.

A metallic cooling member for an internal combustion engine comprisin a. row of narrow annuli adapted to form t e combustion zone walls of the engine cylinders and separated for passage of cooling air between them'; and wide plates, with finned radiating surfaces, connected to and extendin along said row of annuli at'a distance to eit er side thereof.' I

3. The combination with an internal combustion engine cylinder body and head, of

posed'between said body and head to form an element of highly thermo-conductive ma- -ter1al comprising a narrow portion interthe combustion zone wall of the cylinder, 9.

nels for the passage of cooling air.

5. Aninternal combustion engine cylinder having external radiating means, and radiating means connected to the combustion. zone of the cylinder extending outside of and overlappin said radiating means longitudinally of t e cylinder, and se arated from the cylinder to permit access 0 air between. I I

6. An internal combustion engine cylinder having external radiating means, and radiating means comprising a plate connected by heat conducting and radiating webs to the combustion zone of the cylinder, and extending outside of and overlapping said radiating means and the cylinder head...

An internal combustion engine cylinder having external radiating means, and radiating means comprising a plate separated from the cylinder to permit passage of air between extending outside of and overlapping said radiating means and the cylinder head, and connected to. the combustion zone or the cylinder at isolated points by heat conducting and radiatin Weiss.

8. In an internal coiribustion engine, the combination of a row or separated cylinders with radiating means between them and at either side; and radiating plates connected to the combustion zones of the cylinders extending along the row of cylinders at either side outside of and overlapping their radiating means and the cylinder heads, and separated from cylinders and heads to permit access of air between.

9. The combination with an internal combustion engine cylinder, cf a plate for dis sipating heat from the cylinder extending in an axial direction with reference to the cyl- -radiating plate of extensive surface area inder and having radiating means including lateral fins flanked by vertical surfaces projecting therefrom in opposed relation.

10. An internal combustion engine cylinder comprising a portion of wear-resisting metal with external radiating means, and a part of softer and more thermo-conduotive metal including a combustion zone wall and radiating means connected to said combustion zone wall at isolated points b heat conducting and radiating webs, sai last-mentioned radiating means extending outside of radiating means including a late connected to said combustion zone wal by heat conducting and radiating webs and overlapping the wear-resisting portion of the cylinder.

12. An internalcombustion engine comprising separated cylinders with radiating means between them and interconnecting webs, radiating means projecting at either side from cylinders and webs, and radiating means connected to the combustion zones of v the cylinders extending outside of and overlapping said latter radiating means longitudmally of the cylinders and separated therefrom to permit passage of air behind the same to the radiating means last above mentioned.

"13. In aninternal combustion engine, the combination of cylinders with interconnecting webs, radiating fins projecting at either 1 side from cylinders and webs, and radiating means connected to the combustion zones of the cylinders extending outside of and overlappin said radiating fins longitudinally of the cylinders.

14. In an internal combustion engine, the combination of cylinders with interconnectin webs, radiating fins projecting at either the heat so received.

15. In an internal combustion engine, the combination of separated cylinders with radiating means between them and interconnecting webs, radiating means projecting at either side from cylinders and webs, and

radiating means connected to the combustionzones of the cylindersextending outside'bf surface for dissipating the heat so received.

16. In an internal combustion engine, the combination of separated cylinders with radiating means between them and radiating means projecting at either side from the cylinder's, and radiating means connected to the combustion zones of the cylinders extending outside of and overlapping said latter radiating means longitudinally of the cylinders and separated therefrom to permit passage of air behind the same to the radiating means last above mentioned; and a common cylinder head member for said cylinders apertured to permit passage of air between them.

17. The combination of a series of internal combustion engine cylinders cast en bloc with provision of longitudinally extending interspaces between them for passage of cooling air and having longitudinally extending heat radiating fins at the exterior and in the inter-spaces aforesaid, and a radiating element common to said cylinders having apertures registering with the interspaces of the cylinder block and heat radiating fins aligned with those of the cylinders.

18. In an internal combustion engine, the combination with the cylinder and a radiating late finned on its outer face located at a istance from the cylinder and connected thereto by spaced webs affording a multiplicity ofchannels for air fiow at the inner side of the plate, of a casing envelop ing the cylinder and cooperating with the last mentioned fins to form a multiplicity of channels for air flow at the outer side of said plate.

19. In an internal combustion engine, the combination of separated cylinders with radiating means between them and interconnecting webs, radiating means projecting at either side from cylinders and webs, and -radiating means connected to the combustion zones of the cylinders extending outside of and overlapping said latter radiating means longitudinally of the cylinders and se arated therefrom to permit passage of air e- -hind the same to the radiating means last means between them and interconnecting at either webs, radiating means projecting radiating side from cylinders and webs, an

'means connected to the combustion zones of the cylinders extending outside of and overlapping said latterradiating means longitudinally of the cylinders and separated therefrom to permit passage of air behind the same to the radiating means last above mentioned; cylinder heads with intake and exhaust passages therein; valve gear housings surmounting said cylinder heads aifording extended bearing for transfer of heat from the exhaust valve stem and having radiating means on the side thereof nearest the latter; a casing enclosing said cylinders with their radiating means, and

also the aforesaid combustion chamber radiating means; and means for passing cooling air about said valve 1gear housings and said cylinder heads and t rough said casing.

21. In an engine, multiple cylinders cast integral havingbanks of fins arranged in vertical parallel, and a radiatin element joining all the cylinders and amphfying the formation of parallel fins between adjacent cylinders. v

22. In an engine, multiple cylinders cast integral having channels between the cylinders and banks of fins arranged in vertical parallel, a radiating element common to all the cylinders and amplifying the formation of parallel fins between adjacent cylinders, and fins extending into said channels.

23. In an engine, multiple cylinders cast integral havin banks of fins arranged in vertical paralle a removable plate member constituting the combustion chamber, and a continuous radiating element integral with the cylinders to whlch the removable combustion chamber is connected.

24. In an engine, multiple cylinders cast inte ral having banks of fins arranged in vertical parallel and a continuous radiating surface common to all the cylinders, a plate member constituting a removable combustion chamber applied to said radiating surface, and a removable cylinder head having exhaust and intake valves mounted thereon.

As an article of manufacture, a bolting plate for superposition upon engine cylinders and having combustion chambers formed therein, heat radiating plates adaptedito be vertically disposed when the boltin plate is mounted, vertical fins forme on the heat radiating plate, and fins connecting the latter to the bolting plate.

26. As an article of manufacture, a bolting plate for superposition on the cylinders of an engine having heat radiating fins, said bolting plate having openings forming combustion chambers, a heat radiating plate havin fins, and fins connecting said heat radiatlng plate to the bolting plate, the latter being spaced away to overlap the cylinder fins.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylva nia, this 9th day of November, 1921.

JOHN W. SMITH. Witnesses: I

JAMES H. BELL, E. L. FULLERTON. 

